Cement-rock interaction : infiltration of a high-pH solution into a fractured granite core

Within the framework of the HPF project (Hyperalkaline Plume in Fractured Rock) at the Grimsel Test Site (Switzerland), a small scale core infiltration experiment was performed at the University of Bern. A high-pH solution was continuously injected, under a constant pressure gradient, into a cylindrical core of granite containing a fracture. This high-pH solution was a synthetic version of solutions characteristic of early stages in the degradation of cement. The interaction between the rock and the solutions was reflected by significant changes in the composition of the injected solution, despite the negligible pH-buffering capacity, and a decrease in the permeability of the rock. Changes in the mineralogy and porosity of the fault gouge filling the fracture were only minor. Within the new LCS (Long-Term Cement Studies) project at Grimsel, new one-dimensional reactive transport modeling using CrunchFlow has been used to improve the interpretation of the experimental results. Dispersive and advective solute transport, adsorption processes and mineral reaction kinetics have been taken into account. The evolution of solution composition is mainly controlled by dissolution/precipitation reactions. Adsorption processes (cation exchange, surface complexation) only play a role in the very early stages of the experiment

Duration, frequency, and types of children’s activities: potential of a classification procedure

This study investigated the potential of a classification procedure to determine type, duration, and frequency of children's physical activity (PA) during 7 days based on accelerometer data. Hip and wrist accelerometer data (1-second epoch) were collected over a week in 41 children (age: 10.7 ± 0.9 years). The classification procedure was used to assign each second into one of the following four categories: stationary activities, walking, running, and jumping. A diary was used to assess the simultaneous activity setting. Children spent 75.5% of the time (600.9 ± 80.1 minutes/day) on stationary activities, 15.6% (124.6 ± 33.6 minutes/day) on walking, 2% (16.1 ± 8.6 minutes/day) on running, and 1% (4.7 ± 5.2 minutes/day) on jumping. The median duration of stationary activities, walking, running, and jumping was 4, 2, 1, and 1 seconds, respectively. The largest proportion of running and jumping occurred during outdoor sport training (10.7%), physical education classes (6.7%), and vigorous outdoor activity (6.1%). The classification procedure used in this study shows the potential for analyzing children's PA in free-living conditions. The study results revealed that children's PA is characterized by very short activity bouts and that providing the possibility for children to participate in structured or unstructured outdoor activities might increase their PA. Therefore, the classification procedure enhanced the analysis of the transitory nature of children's PA and the understanding of their PA behavior during different activity settings

Recognition of activities in children by two uniaxial accelerometers in free-living conditions

The aim of this study was to develop a classification procedure for accelerometer data to recognize the mode of children’s physical activity (PA) in free-living conditions and to compare it with an established cutoff method. Hip and wrist accelerometer data with an epoch interval of 1 s were collected for 7 days from 24 girls (age: 10.7 ± 1.7 years) and 17 boys (age: 10.6 ± 1.6 years). Videos were recorded during the same 7 days at several points of time at school and during leisure time. Each second of video data was labeled as one of nine activity classes. A classification procedure based on pattern recognition algorithms was trained with the accelerometer data relating to respective video labels of half of the children and tested against the data from the other half of the children. The overall recognition rate of the classification procedure was 67%. The procedure was able to classify 90% of stationary activities, 83% of walking, 81% of running and 61% of jumping activities. The remaining activities could not be recognized by the main classifier. This study developed a classification procedure based on well-accepted accelerometers and video recordings to recognize children’s PA in free-living conditions. It has been shown to be valid for the activities of being stationary, walking, running and jumping. In contrast to former measurement and analysis procedures, this method is able to determine the modes of specific activities among children. Consequently, the presented classification procedure provides additional information on the PA behavior in children registered by established accelerometers

Assembling and Verification of a Fitness Test Battery for the Recruitment of the Swiss Army and Nation-Wide Use

The aim of this study was to assess the reliability, validity and feasibility of selected physical performance tests, to compile a new fi tness test battery based on these results and to obtain standard values for young men. 79 men (20.3 ± 1.1 y) performed the tests for the reliability part, while 60 men (20.3 ± 1.1 y) completed the tests for the validity part of the study. Feasibility was confi rmed by 25 sport experts who conducted the test battery among 1704 men (19.5 ± 1.0 y). For standard values, the data of 12 862 men (19.9 ± 1.0 y) were collected. Based on the reliability and validity data, the following 5 tests were selected for the fi tness-test battery: 1) progressive endurance run, 2) seated 2-kg-shot put, 3) standing long jump, 4) trunk muscle strength test and 5) 1-leg standing test. The reliability and validity of the selected performance tests were suffi cient to very good (r = 0.50–0.90 and r = 0.64–0.91, respectively). The suggested fi tness-test battery can be applied among large groups

Iodide interaction with natural pyrite

129I is one of the major dose-determining nuclides in the safety analysis of deep storage of radioactive waste. Iodine forms anionic species that hardly sorb on the surfaces of common host-rock minerals. Recently, interest has arisen on the role of pyrite, an accessory mineral capable of binding anionic selenium. Whereas the interaction of selenium with pyrite is well documented, corresponding results on iodine sorption are still scarce and controversial. Pyrite is present in argicilleous rocks which are being considered in many countries as potential host rocks for a radioactive waste repository. The uptake of iodide (I−) on natural pyrite was investigated under nearly anoxic conditions (O2<5ppm) over a wide concentration range (10−11-10−3 M total I−) using 125I as the radioactive tracer. Weak but measurable sorption was observed; distribution coefficients (Rd) were less than 0.002m3kg−1 and decreased with increasing total iodide concentration. Iodide sorption was connected to the presence of oxidized clusters on the pyrite surface, which were presumably formed by reaction with limited amounts of dissolved oxygen. The results obtained indicated that pyrite cannot be considered as an effective scavenger of 129I under the geochemical conditions prevailing in underground radioactive waste geologic storag

Physical performance in young men at Swiss Army recruitment 1982 to 2005

Little is known about the physical fitness profiles of the young Swiss population. The purpose of the present work is to describe the data of the physical performance tests at the compulsory Swiss Army recruitment. The 12-minute running test, the standing long jump, and the five-meter pole-climbing test were continuously part of the physical performance test for more than 20 years. These data show a decrease in aerobic endurance and pole-climbing performance from 1987 to 2002. After 2002 a reversal of trend occurred for the aerobic endurance performance. Muscle fitness, assessed by standing long jump, has not changed. The inconsistent data do not confirm the common opinion of a decreasing general physical fitness level among Swiss men

Correlates of children’s physical activity during physical education classes

Aim: The aim of this study was to investigate the influence of correlates on physical activity (PA) during physical education (PE). Method: One hundred and ninety children (11.2 ± 0.8 y, 1.5 ± 0.1 m, 37.7 ± 8.3 kg) of 12 classes participated. Children were asked to wear an accelerometer for seven days. Teachers filled in a questionnaire to collect data about correlates of PA during PE (i.e. sex, weight, age of children, daily PA of the children, class size, PA behavior and formation of the teacher and size of gym). Correlates for moderate-to-vigorous PA (MVPA) during PE were determined using multifactor linear regression analysis. Results Fifty-three percent of the variability of MVPA during PE was explained by the investigated correlates. Apart from individual correlates (sex, weight, age), PE taught in small classes and large gyms by a PE specialist and a high overall PA of the child had independent positive effects on MVPA during PE. Conclusion: The results underline the importance of small PE classes taught by specialized PE teachers in large gyms and the increase of overall PA of children for effective future intervention studies and for political discussion focusing on increasing PA during PE

Enhanced soil quality with reduced tillage and solid manures in organic farming - a synthesis of 15 years

Demands upon the sustainability of farming are increasing in step with climate change and diversity loss. Organic farming offers a viable approach. To further improve organic management, three strategies with potential to enhance soil quality are being tested in a long-term trial since 2002 on a clay loam in temperate Switzerland: reduced tillage vs. ploughing, solid vs. liquid manures and biodynamic preparations. A synthesis of 15 years reveals an increase in topsoil organic carbon (SOC, +25%), microbial biomass (+32%) and activity (+34%) and a shift in microbial communities with conversion from ploughing to reduced tillage. Soils under reduced tillage are more stratified in SOC and nutrients. Additional application of composted manure has increased SOC by 6% compared to pure slurry application, with little impact on soil microbes. Biodynamic preparations have had a minor impact on soil quality. Fertilisation and biodynamic preparations did not affect yields. Both higher and lower yields were harvested in the reduced tillage system in relation to ploughing. The main yield determinants were N supply and higher weed infestation under reduced tillage. Continuously reduced tillage in organic farming has been proven to enhance soil quality at this site, while also presenting more challenges in management

Physical activity and health – what are the recommendations and where do we find the Swiss population?

Since 1999 Switzerland has physical activity recommendations for adults, since 2006 also for school-age children and adolescents. The best available estimates indicate that 32% of adults meet the recommendations for three endurance-type training sessions and another 9% the minimal recommendations of half an hour moderate intensity physical activity on most days of the week. 13% of Swiss adolescents seem to meet the minimal recommendations of one hour on every day of the week, 35% on five days per week. These data rely on standardised, nationally representative surveys providing robust estimates, but they are based on self-report instruments of untested, poor or questionable validity against objective measurements of physical activity. No nationally representative data is available on compliance of children with the recommendations. Physical activity recommendations for all age groups in Switzerland should be reviewed in the light of the WHO recommendations expected for 2010. Established national surveys should be continued to allow the description of trends. In addition, physical activity behaviour of children and other age groups should be assessed using internationally standardised and nationally validated questionnaires and objective measurements. The feasibility of physiological measurements at the population level should be explored